1. From the Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland;2Helen Keller International, New York, New York;
2. Helen Keller Mexico, Chihuahua, Mexico;
3. IEEPO/Ver Bien, Oaxaca, Mexico;
4. Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland; and
5. From the Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland;5Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland; and
6. Department of Ophthalmology and Visual Science, Chinese University of Hong Kong, Hong Kong SAR.